Roll Observatory packages and add a roll script

stack_trace/lib/src/utils.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library stack_trace.src.utils;
-
-/// Returns [string] with enough spaces added to the end to make it [length]
-/// characters long.
-String padRight(String string, int length) {
-  if (string.length >= length) return string;
-
-  var result = new StringBuffer();
-  result.write(string);
-  for (var i = 0; i < length - string.length; i++) {
-    result.write(' ');
-  }
-
-  return result.toString();
-}
-
-/// Flattens nested lists inside an iterable into a single list containing only
-/// non-list elements.
-List flatten(Iterable nested) {
-  var result = [];
-  helper(list) {
-    for (var element in list) {
-      if (element is List) {
-        helper(element);
-      } else {
-        result.add(element);
-      }
-    }
-  }
-  helper(nested);
-  return result;
-}